Speed pump for hydraulic jacks

ABSTRACT

An unseated, pressure-responsive ball valve mechanism connects the speed pump of a two-speed hydraulic ram unit to the reservoir when the load on the ram reaches a level demanding the higher pressures produced by the power pump.

United States Patent [72] Inventor James R. Laundy [56} References Cit d lslggllsigswm. UNITED STATES PATENTS all; g 1969 1,951,398 3/1934 Dearsley 103/11 A Patented July 20 1971 2,440,060 4/1948 Page 60/52 HA (73] Assi nee Tenn; Inc 2,613,437 10/1952 McPhee 60/52 HA UX g Houston 2,691,503 10/1954 Bigelow 60/52 HA UX 3,142,156 7/1964 Mills et a1. 60/52 HA 3,307,482 3/1967 Lauck 103/42 X Primary ExaminerEdgar W. Geoghegan [54] SPEED PUMP FOR HYDRAULIC JACKS Attorney-Harness, Dlckey & Pierce 5 Claims, 4 Drawing Figs.

[52] US. Cl 60/52 HA, ABSTRACT: An unseated, pressure-responsive ball valve 417/254 mechanism connects the speed pump of a two-speed hydraulic [51] lnLCl FlSb 15/18 ram unit to the reservoir when the load on the ram reaches a 50] Field of Search... 60/52 HA; 1 level demanding the higher pressures reduced b the ower P Y P 103/11 C; 137/539;417/254, 265 pump.

PATENTED JUL20 |97| 3 593; 520

sum 2 OF 2 INVENTOR.

\li/vrm f 1101/; B Y

SPEED PUMP FOR HYDRAULIC JACKS DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a hydraulic pressure ram unit embodying the invention;

FIG. 2 is a longitudinal section along the line 2-2 of FIG. I with the speed pump rotated for clarity into the plane of the section;

FIG. 3 is a section along the line 33 of FIG. 1; and

FIG. 4 is an enlarged section along the line 44 of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION The hydraulic ram assembly 1 has an outer cylinder 3 and an inner cylinder 5 each of which are secured in fiuidtight engagement to a base member 7, the space between the cylin ders 3 and 5 comprising a reservoir 9 for hydraulic liquidfor oil. The inside of the cylinder 5 constitutes an operating chamber 11 for the ram 13 which extends out of the cylinders through a suitable packing and gland assembly 15 whereby its outer end 17 may be connected in a suitable manner to a load to be moved. The ram 13 has suitable packing 19 at its inner end to form a pressure-receiving face that slides on but is 'in fluidtight engagement with the chamber wall 11, the space 21 between the pressure end 19 and the casting 7 comprising a ram pressure-applying chamber. As this chamber is enlarged the ram 13 will move outwardly and oil within the chamber 11 on the low-pressure side of the ram end 19 can flow through orifices 23 back to the reservoir9.

Two different pump pistons are mounted inside of the housing 7 for furnishing oil from the reservoir 9 at different rates to the ram pressure chamber 21 whereby the ram 13 may be moved quickly under no'load conditions and then more slowly but with power under load conditions. The speed pump piston 25 for no-load conditions is relatively large in diameter (large displacement per stroke) as seen in FIG. 2 and works within'a chamber or bore 27 in the base 7 and has an outer end 29 projecting out of the base. The power pump piston 31 as seen in FIG. 3 for supplying pressure oil under load conditions is considerably smaller and works in chamber or bore 33 in the housing 7 and has an outer end 35 extending out of the base 7. A transverse pin 37 extends through the speed pump end 29 and the power pump end 35 and through two sides of a'pump handle receiving linkage 39 whereby the two pumps may be simultaneously reciprocated in their respective bores by movement of a pump handle or other suitable power supply mechanism (not shown).

Each pump has a hydraulic circuit which enables it to withdraw oil from the reservoir 9 on its suction stroke and force it into chamber 21 on its pressure stroke. The circuit for the speed pump 25 includes means operative when a load is on the ram 13 for connecting the speed pump to the reservoir on its pressure stroke and also includes a connection to a release valve for relieving pressure in the chamber 21 when desired. The circuit for the power pump 31 includes a connection to an overload or maximum pressure valve that connects power pump displacement to the reservoir if pressure demands exceed a safe level;

Referring first to FIGS. 2 and 4 which show the hydraulic circuit for the speed pump 25, the inner or pressure'end of the speed pump cylinder 27 is connected through intersecting passages 41 and 43 to a speed pump control passage 45.. The passage 45 is intersected by a passage 47 which connects to an enlarged section 49 and then opens into the reservoir 9 via a filter 51. The passage 45 also is intersected by the passage 53 which connects it to the ram-working pressure chamber 21. The passage 45 is'further intersected be a release valvc flow passage 55 which opens into a valve bore 57 containing the manually rotated release valve mechanism 59. When the valve 59 is' unseated oil flows from chamber 21 through passage 53 into passagc 45 and then through passage 55 past the.valve 59 through a suitable passage (not shown) to the reservoir 9 so that the ram 13 can be retracted into the cylinder 11 at a desired rate of speed.

Seated in the bottom of the speed control passage45 is a coil spring 61 which in its extended condition holds a floating reservoir control ball cheek valve 63 that fits rather closely to the wall of passage 45 above the inner section of the reservoir passage 47 with the passage 45. The spring 61 is chosen so that when the pressure in the passage 45 above the ball 63 increases a slight amount above that required to move ram 13 under a no-load condition the ball 63 will be depressed below the suction passage 47 whereby oil will flow to the reservoir on the pressure stroke of speed pump piston 25. On the suction stroke the ball 63 can move to theenlarged portion 62-of the passage 45 to facilitate flow to the speed pump bore.

The passage 45 also contains a sleevelike seat insert 64 for the ram control ball check valve 65 which is held on its seat on the enlarged top of the insert 64 by a coil spring 67 whose compression is maintained by a plug 69 that is threaded into the base 7 at the outer end of the passage 45. Under no-load on-ram conditions the ball 65 is unseated to permit oil displaced by speed' pump 25 to reach ram chamber 21' through intersects the power pump control passage 75 that extends in base 7 substantially parallel to the speed pump control passage 45. The lower and small end of the passage 75 intersects a passage 77 which leads-to the reservoir 9 via a filter 79. The

passage 75 is also intersected by a passage 81 (FIG. 3) which connects it to the ram-working pressure cylinder 21. The power control passage 75 is enlarged to form a valve seat 83 for a reservoir control ball check valve 85, upward movement of the ball 85 being limited by contact with the bottomend of a sleevelike valve insert 87 which provides a valve seat at its enlarged top end for a ram control ball check valve 89. The upward movement of the ball 89 is controlled by contact with a limit 91 as carried by a plug 93 which is threaded into the base 7 at the outer end ofpassage 75.

As seen in FIG. 4, a pressure relief or antioverload valve mechanism 95 is disposed in a passage 97 in the base 7 which is parallel to the passages 45 and 75. The mechanism 95 comprises spring-pressed, cupshaped valve seat member 99 having an aperture 101 in the bottom thereof which presses spring 109, which is adjusted in compression by the threaded plug 111 in thepassage 97, controls thepressure required to I lift the valve 103 from its seat 105 so that oil may flow from passage 73 to a passage 113 that intersects the passage 97 and V leads to the reservoir 9.

The operation of the unit 1 is believed to be evident from the preceding description. It will be seen that the construction;

is relatively simple for the hydraulic circuitry involved and adapted to efficient manufacture and durable operation.

Iclaim:

l. A hydraulic ram unit comprising a housing providing a; reservoir and a ram chamber, a base secured to said housing and providing the pressure end of said ram chamber, a ram in said chamber having a pressure end in the housing and a load attachment end extending out of said housing, said base having a speed pump chamber with a speed pump piston therein, said base having a power pump chamber with a power pump piston therein, said base having a speed pump control passage with first and second ends and a power pump control passage with first and second ends, said base having a ram passage opening into the pressure end of the ram chamber and communicating at a first point with said speed pump control passage and a power ram passage opening into the pressure end of the ram chamber and communicating at a first point with said power pump control passage, said base having a speed reservoir passage opening into said speed pump control passage at a second point and connecting it to said reservoir and a power passage communicating with said power pump control passage at a second point and connecting it to said reservoir, said base having a speed pump flow passage connecting the pressure side of the speed pump chamber to the speed pump control passage at a third point located between said first and second points in said speed pump control passage, said base having a power pump flow passage connecting the pressure side of the power pump chamber to the power pump control passage at a third point located between the first and second points in said power pump control passage, a ram control valve seat in said speed pump control passage and located between said first and third points, a ram control check valve on said valve seat arranged to unseat to provide for pressure flow from the speed pump piston to the ram chamber, an unseated reservoir control valve in said speed pump control passage and movable by fluid pressure to positions on either side of said second point, spring means biasing said ram reservoir control valve to a position between said second and third points, and check valve means in said power pump control passage controlling pressure flow from said third to said first points and suction flow from said second to said third points.

2. A unit as set forth in claim I wherein said reservoir control valve comprises a ball, said ball being of substantially the same diameter as the diameter of the portion-of the speed pump control passage in which the ball is located.

3. A unit as set forth in claim 1 and including a coil spring seated in the end of said speed pump control passage and providing said spring means.

4. A unit as set forth in claim 3 wherein said control passages are parallel to each other and are threaded adjacent their first ends, and plugs threaded in said threaded portions of said passages and providing means for controlling the movement ofthe pressure flow check valves.

5. A hydraulic ram unit comprising a housing providing a reservoir and a ram chamber having a pressure end, a ram in said chamber having a pressure end in the housing and a load attachment end extending out of said housing, a hydraulic circuit assembly having fiow passage connections with said reservoir and ram chamber, said assembly having a speed pump chamber with a speed pump piston therein, said assembly having a power pump chamber with a power pump piston therein, said assembly having a speed pump control passagewith first and second ends and a power pump control passage with first and second ends, said assembly having a ram passage connecting with the pressure end of the ram chamber and communicating at a first point with said speed pump control passage and a power ram passage connecting with the pressure end of the ram chamber and communicating at a first point with said power pump control passage, said assembly having a speed reservoir passage opening into said speed pump control passage at a second point and connecting it to said reservoir and a power reservoir passage communicating with said power pump control passage at a second point and connecting it to said reservoir, said assembly having a speed pump flow passage connecting the pressure side of the speed pump chamber to the speed pump control passage at a third point located between said first and second points in said speed Hump control passage, said assembly havin a power pump ow passage connecting the pressure side 0 the power pump chamber to the power pump control passage at a third point located between the first and second points in said power pump control passage, a ram control valve seat in said speed pump control passage and located between said first and third points, a ram control check valve on said valve seat arranged to unseat to provide for pressure flow from the speed pump piston to the ram chamber, an unseated reservoir control valve in said speed pump control passage and movable by fluid pressure to positions on either side of said second point, spring means biasing said ram reservoir control valve to a position between said second and third points, and check valve means in said power pump control passage controlling pressure flow from said third to said first points and suction flow from said second to said third points. 

1. A hydraulic ram unit comprising a housing providing a reservoir and a ram chamber, a base secured to said housing and providing the pressure end of said ram chamber, a ram in said chamber having a pressure end in the housing and a load attachment end extending out of said housing, said base having a speed pump chamber with a speed pump piston therein, said base having a power pump chamber with a power pump piston therein, said base having a speed pump control passage with first and second ends and a power pump control passage with first and second ends, said base having a ram passage opening into the pressure end of the ram chamber and communicating at a first point with said speed pump control passage and a power ram passage opening into the pressure end of the ram chamber and communicating at a first point with said power pump control passage, said base having a speed reservoir passage opening into said speed pump control passage at a second point and connecting it to said reservoir and a power passage communicating with said power pump control passage at a second point and connecting it to said reservoir, said base having a speed pump flow passage connecting the pressure side of the speed pump chamber to the speed pump control passage at a third point located between said first and second points in said speed pump control passage, said base having a power pump flow passage connecting the pressure side of the power pump chamber to the power pump control passage at a third point located between the first and second points in said power pump control passage, a ram control valve seat in said speed pump control passage and located between said first and third points, a ram control check valve on said valve seat arranged to unseat to provide for pressure flow from the speed pump piston to the ram chamber, an unseated reservoir control valve in said speed pump control passage and movable by fluid pressure to positions on either side of said second point, spring means biasing said ram reservoir control valve to a position between said second and third points, and check valve means in said power pump control passage controlling pressure flow from said third to said first points and suction flow from said second to said third points.
 2. A unit as set forth in claim 1 wherein said reservoir control valve comprises a ball, said ball being of substantially the same diameter as the diameter of the portion of the speed pump control passage in which the ball is located.
 3. A unit as set forth in claim 1 and including a coil spring seated in the end of said speed pump control passage and providing said spring means.
 4. A unit as set forth in claim 3 wherein said control passages are parallel to each other and are threaded adjacent their first ends, and plugs threaded in said threaded portions of said passages and providing means for controlling the movement of the pressure flow check valves.
 5. A hydraulic ram unit comprising a housing providing a reservoir and a ram chamber having a pressure end, a ram in said chamber having a pressure end in the housing and a load attachment end extending out of said housing, a hydraulic circuit assembly having flow passage connections with said reservoir and ram chamber, said assembly having a speed pump chamber with a speed pump piston therein, said assembly having a power pump chamber with a power Pump piston therein, said assembly having a speed pump control passage with first and second ends and a power pump control passage with first and second ends, said assembly having a ram passage connecting with the pressure end of the ram chamber and communicating at a first point with said speed pump control passage and a power ram passage connecting with the pressure end of the ram chamber and communicating at a first point with said power pump control passage, said assembly having a speed reservoir passage opening into said speed pump control passage at a second point and connecting it to said reservoir and a power reservoir passage communicating with said power pump control passage at a second point and connecting it to said reservoir, said assembly having a speed pump flow passage connecting the pressure side of the speed pump chamber to the speed pump control passage at a third point located between said first and second points in said speed pump control passage, said assembly having a power pump flow passage connecting the pressure side of the power pump chamber to the power pump control passage at a third point located between the first and second points in said power pump control passage, a ram control valve seat in said speed pump control passage and located between said first and third points, a ram control check valve on said valve seat arranged to unseat to provide for pressure flow from the speed pump piston to the ram chamber, an unseated reservoir control valve in said speed pump control passage and movable by fluid pressure to positions on either side of said second point, spring means biasing said ram reservoir control valve to a position between said second and third points, and check valve means in said power pump control passage controlling pressure flow from said third to said first points and suction flow from said second to said third points. 